Method and apparatus for cooling granular contact material



May 6, 1958 F. c. FAHNESTOCK I 3 METHOD AND APPARATUS FOR coou'Nc GRANULAR CONTACT MATERIAL Filed Dec. 3, 1952 4 Sheets-Sheet 1 fig! mm? WW5? 15 3 SE/IL 60$ 14 uau/o Fm) v/WR 550 INVENTOR zfs M May 6,1958 F. c. FAHNESTOCK METHOD AND APPARATUS FOR COOLING GRANULAR CONTACT MATERIAL Filed Dec. 3,. 1952 4 Sheets-Sheet 2 w QHBH QHHQ a May 6, 1958 F. C. FAHNESTOCK METHOD AND APPARATUS FOR COOLING GRANULAR CONTACT MATERIAL Filed Dec. 3, 1952 4 Sheets-Sheet 3 May 6 1 958 FAHNESTOCK METHOD AND APPARATUS FOR COOLING GRANULAR coNTAcT MATERIAL Filed Dec. 3, 1952 4 Sheets-Sheet 4 ATTORNfi INVENTOR A 29115 ifiyzriafi W 0 10 64 aw y ufi v a United States Patent METHOD AND APPARATUS FQR COOLING GRANULAR CONTACT MATERIAL Frank C. Fahnestock, Manhasset, N. Y., assignor to Socony Mobil Oil Company, Inc., a corporation of New York Application December 3, 1952, Serial No. 323,764

8 Claims. (Cl. 252-418) This invention pertains to the cooling of gravitating compact masses of solid hot contact material. It is particularly directed to an improved method and apparatus for extracting heat from a gravitating substantially compact mass of particle-form contact material in a moving bed hydrocarbon conversion system.

Many processes, such ascracking, polymerization, reforming, coking and desulfurization, use gravitating columns of granular contact material in an enclosed cyclic system. For example, in cracking heavy petroleum stocks to produce lighter hydrocarbons, preferably boiling in the gasoline boiling range, the granular material is gravitated as a substantially compact bed through a reaction zone where it is contacted with hydrocarbons to effect the cracking reactions and the converted products are withdrawn continuously from the bed. During gravitation through the reaction zone, the particles of contact material acquire a deposit of carbonaceousmaterial, commonly referred to as coke, which must be removed periodically. The particles are withdrawn from the bottom of the reaction zone and transferred to the top of a reconditioning zone. In the reconditioning zone, the particles are gravitated as a substantially compact mass and blown with air toeifect the combustion of the coke. Flue gases are removed from the zone continuously carrying with them some of the heat released by the burning. The regenerated contact material is withdrawn from the bottom of the reconditioning zone and transferred to the top of the reaction zone.

The particles may be catalytic in nature or not. Catalysts, such as natural of activated clays, bauxite, montmorillonite, etc., are well known in the hydrocarbon art, as are synthetic hydrogels of alumina, chromia, etc. When the process is coking or visbreaking, where only thermal cracking may be involved, the particles may be formed of inert material, such as fused quartz, iron balls, coke particles or Carborundum. Cracking reactions I the cooling fluid is prevented from flowing through the tubes, the tube reaches the temperature of the vessel. The cooling fluid is kept at a temperature substantially below the temperature of the contact material and thus when the fluid is first passed through the hot tubes, the metal is subjected to a thermal shock. This has caused rupture of the pipes with a release of the fluid. Although efforts to relieve this difficulty have been tried, none have been really successful.

It has been suggested that the trouble may be avoided by using a catalyst circulating rate which is high enough to permit the particles to be passed through the kiln without cooling and by using a catalyst cooler outside the regenerator as a means of balancing the heat transfer in the system. For example, in catalytic cracking it is usually necessary to extract some heat from the solids after regeneration to prevent the reaction temperature from rising to too high a level. The cooler suggested is one in which the cooling fluid is kept in contact with the entire heat exchange surface at all times and the degree of cooling is varied by varying the volume of catalyst in contact with the cooling surface at'any given instant. Such a cooler is shown and claimed in copending applications for United States Patents, Serial Number 154,130, filed April 5, 1950, now Patent No. 2,690,057, and Serial Number 148,669, filed March 9, 1950, now Patent No. 2,690,056. These coolers, while they are a substantial improvement'over the prior art, have some undesirable features. They cannot be located within the regenerator, especially where gas transfer is being effected, becauseof the open passages through the cooler. Also, where the metal of the cooler is not contacting hot contact material,

the temperature drops below the temperature of the metal 7 in contact with the contact material. This causes undesirable temperature stresses to be set up in the metal, which may cause cooler failure.

It is an object of this invention to provide a cooler and method of cooling contact material in which the entire area of the cooling surface is maintained in contact with cooling fluid at all times.

It is a further object of this invention to provide an improved cooler and method of cooling hot contact material in which the entire area of the cooling surface, is maintained in contact with cooling fluid at all times and the cooler can be located within 'a regenerating zone for use in preventing the contact material temperature from rising to heat-damaging levels.

It is a further object of this invention to provide an improved regenerator and method of regenerating conhave been found to occur most readily at a temperature of about 800-l000 F. and at an advanced pressure, for example, 530 p. s. i. (gauge). It is desirable, of course, to complete the reconditioning of the material as rapidly as possible and, therefore, high temperatures are used in the kiln or reconditioner, in the neighborhood of 1000-1300 F. The upper limit of temperature in the kiln is generally limited by the catalyst, because it has been found that catalytic materials lose their activity if .they are heated much in excess of about 1300 F. When catalytic materials are being regenerated, therefore, it istact material in which heat is extracted by a heat exchanger section in adjustable amounts necessary to main-. tain the temperature of the contact material within the desired operating range and yet the entire surface of the heat exchanger is maintained in contact with cooling fluid at all times. j I

These and other objects of the invention will be made more apparent in the following detailed description of the invention, made with reference to the attached diagrammatic sketches.

One broadaspect of the invention involves the passage of a substantially compact mass of hot solids through an upright vessel which has a cooling section in which cooling pipes are distributed across the vessel. A horizontal'partition is located above the cooling pipes and depending conduits, uniformly distributed across the partition, are terminated at a level above the pipes. Vertical partitions are located between the pipes, distributed across the vessel. The vertical partitions divide the vessel crosssection into vertical catalyst flow paths, some of which are located in vertical alignment with the depending conduits and some of which are located laterally displaced from said conduits. The conduits are terminated at their lower ends at a .level above the partitions which is sufiicient to permit the catalyst to spread laterally from the conduits to cover the entire cross-section of the vessel above the vertical partitions. Therefore, all the .flow paths over the cooling conduits are filled with catalyst. However, extension members are provided about the depending conduits, designed to be raised or lowered about the conduits. When the members are lowered, the catalyst does not spread laterally at the bottom of the depending conduits, but is kept confined laterally to a lower level. This level is close enough to the vertical partitions, so that the catalyst fills only those paths directly below the depending conduits and does not fill those flow paths laterally, :displacedxfrom the depending conduits. The catalyst is gravitated through the kiln in substantially compact .columnar condition, and hence forms a bed surface atthe angle of repose of the catalyst, usually about 30 degrees with the horizontal, when released from lateral confinement. Therefore, where the catalyst is released from the bottom of the extension members at such a level that an imaginary line drawn downwardly and outwardly from the edge of the extension rnember at about 30 degrees with the horizontal intersects a vertical line through the adjacent vertical partitions below the top of said partitions, only the flow path directly beneath the conduit will be filled. The cooling conduits are kept filled with cooling fluid at all times, but the volume of hot catalyst in contact with the cooling pipes at any instant is adjusted to provide the desired catalyst temperature. It is seen that any desired amount of cooling may be performed withoutchanging the total flow rate of the catalyst through the regenerator orwithout stopping the flow of cooling fluid through any of the cooling pipes. I Figure l is a diagrammatic showing ofa moving bed conversion system.

Figure 2 is a vertical sectional view of a kiln showing the improved cooling section incorporated therein.

Figure 3 is a vertical sectional view of the kiln of Figure 2 as seen on plane 33 of Figure 2.

Figure 4 is a plan view of the kiln of Figure 2 as seen on plane 44 of Figure 2.

Figure 5 is a vertical sectional view of a multistage kiln incorporating the improved cooling section.

Throughout the views, similar reference characters refer to similar parts. Referring to Figure l, a general system for the conversion of hydrocarbons in the presence of a moving bed of granular contact material is shown. A reactor is shown alongside a regenerator or kiln 11. Above the reactor is a storage hopper 12 connected to the top of thereactor by an elongated conduit or gravity feed leg 13. An elevator 19 of the bucket type is located between the vessels. The connecting conduit 20 is connected between the bottom of the reactor and the bottom of the elevator 19. The conduit 21 is connected between the top of the elevator and the top of the regenerator 11. A second elevator 22 is located between the vessels. Theconduit 23 is connected between the bottom of the regenerator 11 and the bottom of the elevator 22. The conduit 24 is connected between the top of the elevator 22 and the hopper 12.

The kiln cross-section is shown on Figures 2, 3 and 4. A partition 25 is located horizontally across the upper portion of the vessel. The region located below the partition 25 is utilized for reconditioning the particles. A multiplicity of pipes 26 are attached to the vessel at spaced levels to supply air for combustion from the commen pipe 27. A multiplicity of pipes 28 are attached at levels intermediate the pipes. 26 for removal of the hue gas through the common pipe 29. Pipes 30, 31 are attached to cooling sections 32, 33. The cooling sections 32, 33 are formed by headers 40, 41 and horizontal pipes 34 passed through the vessel 11. Referring specifically to Figure l, pipes 35, 36 are attached to the cooling sections to effect removal of the cooling fluids. Pipe 37 is .connected between pipes 30, 31 and pipes 35, 36.

A pump 38 and cooler 39 is located in the pipe 37. t

Figure 3 shows a circulating cooling system for cooling solids at a single level. The connecting pipe 37 is located between headers 40 and 41 and has incorporated in it a pump 38 and cooler 39.

Referring particularly to Figures 2, 3 and 4, the gas introduction and collecting channels 43 are located at spaced levels along the vessel 11. A partition plate 44 is located horizontally across the vessel at an intermediate level. Jrop pipes 45 are located uniformly across the partition 44 and have extensions 46 about them which telescope the drop pipes, permitting the pipes to be lengthened or shortened. The extension members 46 shown comprise boxes with holes in their upper ends and open lower ends. The holes in each box fit one row of drop pipes. The extension members are raised by cranks 47, 47, mating bevel gears l8, 4-8, vertical shafts 49, 49.

The shafts 4-9, 49 are threadably engaged with the lugs 51?, 59 on the sides of the extension members. Vertical partitions 31, 51 are located across the vessel in the region occupied by the cooling pipes 34. These partitions divide the vessel into a plurality of paths 51 51, some of which are directly below the conduits 45, whereas others are laterally displaced therefrom.

in operation, the catalyst is gravitated as a continuous column downwardly from the hopper 12, through the elongated. seal leg 13, reactor 10 and conduit 20 to the bottom of the elevator 19. The how of the catalyst is controlled by the valve 51 in the conduit 20. The seal leg 13 is made long enough to permit the solids to feed smoothly into the reactor against the advanced pressure therein. The seal leg deters reactant gas from travelling upwardly. A seal gas in introduced through the conduit 14 into the top of the reactor 1% at a pressure slightly higher than reactor pressure to prevent reactants from flowing upwardly through the column of catalyst. The.

reactants may be charged in liquid form, vapor form or a mixture of both. The vapors travel downwardly through,

the voids in the catalyst bed and the converted products are withdrawn at the bottom of the bed. A stripping gas is introduced into the bottom of the bed of catalyst to remove vaporizable hydrocarbons from the catalyst.

The catalyst removed from the bottom of the bed is contaminated with carbonaceous deposits or coke and is, therefore, transferred by the bucket elevator to the top of the kiln.

The contact material is gravitated as a compact mass through the kiln. The region above the partition 25 in the upper portion of the kiln serves as a surge space, providing storage room for catalyst in the event of unbalance in the rate of flow of catalyst through the elevators. Air is blown into the bed of catalyst at staged levels through alternate channels 43 to travel upwardly and downwardly through the bed to the next adjacent channel. The flue gas is removed from the bed at levels intermediate the levels of gas introduction.

Referring now to Figures 2, 3 and 4, which illustrate the use of a single cooling section at an intermediate level in the kiln, details of the invention will be pointed out with more particularity. The solids are cooled by passage over cooling pipes 34. The pipes are distributed across the column. The horizontal partition 44 is located just above the, cooling pipes and the drop pipes 45 are distributed uniformly across the partition. When the extension members 46 are in the upper position, the lower ends of all the drop pipes 45 are at a uniform level substantially above the top of the vertical partitions. The level of the bottoms of the pipes is sufficiently above the tops of said vertical partitions so that the catalyst expands laterally to cover the entire crossof catalyst into contact with the cooling pipes and provides maximum cooling. Lines drawn downwardly and outwardly from the lower ends of the pipes 45 or the lower ends of the extension members, if they are below the bottom of the pipes 45, at the angle of repose of the catalyst, usually about 30 degrees with the horizontal, must pass over the top of the adjacent vertical partitions in order for catalyst to feed intothc laterallydisplaced flow paths. When less cooling is desired the extension members are lowered. The catalyst discharged from the members forms a bed surface which slopes with respect to the horizontal at about the angle of repose of the catalyst. For commercial catalyst this is about 30 degrees, but for other particles, it may vary fiom about 2545 degrees with the horizontal. When the members are low enough so that lines drawn downwardly and outwardly from the lower edge of the members intersect a vertical line drawn through the nearest adjacent vertical partitions below the top of the partition, the flow of catalyst is restricted to the flow paths directly below the conduits 45 and is excluded from the other paths. Below the vertical partitions the catalyst expands to again cover the entire cross-section of the vessel. However, in the cooling region, the volume of catalyst in contact with the cooling area has been materially reduced. Less cooling is effected, therefore, when the extension members are in the down position.

If the extension members 46 were not present, or when they are in the up position, the catalyst discharged from the pipes 45 would expand laterally in the form of frusto-conical piles, having sidewalls disposed at about 30 degrees. The lower ends of the conduits should be far enough above the upper ends of the partitions 51, so that the piles intersect in a horizontal plane above the top of the vertical partitions 51.

Additional air may be blown through the column at staged levels below the cooling section as shown on the drawings. Although only one cooling section is shown on the drawings, in Figures 2, 3 and 4, it is undersood that several sections may be used at staged levels to meet the particular cooling requirements of any process. It is seen that all cooling pipes are maintained at all times in contact with cooling fluid. The thermal shocks involved in prior art coolers or cooling sections of the kiln' are, therefore, avoided. It is seen also that no valves, star wheels or mechanical throttling device need be used in the catalyst column. This is highly desirable in moving bed conversion processes, because throttling devices have been found to provide operating difficulties and also grind the catalyst to produce objectionable fine particles. I

Figure 5 shows a view of the kiln in which two cooling sections are provided and combustion-supporting gas is introduced under each partition. The partition 44 and drop pipes 45 provide a plenum region which serves the purpose of a gas introduction manifoldand takes the place of one of the manifolds 43. Gas is introduced into the plenum space via the pipe 26. By-pass pipes 60 are provided in the partitions to permit a portion of the gas to pass upwardly through the partition into the catalyst bed above the partition. This stream of'gas is withdrawn from the next higher manifold via the pipe 28. The by-pass pipes 60 have inverted channels or hoods 61 located above them to bafiie the catalyst away from the pipes and prevent the catalyst from passing downwardly through these pipes. The remainder of the gas introduced under the partition passes'downwardly through the catalyst to the next lower withdrawal manifold. This method of gas introduction into the'column provides a split-flow multi-stage .kiln of minimum height.

The conduits 45, used to transfer catalyst from the bed above the partition to the bed below are staggered horizontally across the vessel at the various levels, so that the temperature of the catalyst is made more uniform. Thus, as shown in Fig. 5, catalyst passed through any drop pipe is drawn from the region belowseveral of the drop pipes of the partition located next above the partition to which the particular drop pipe is attached. This provides a constant mixing of portions of the catalyst passing through the different cooling paths, thereby maintaining uniform temperatures across the column. I

The solids withdrawn from the bottom of the kiln are transferred to the hopper atop the reactor for reuse. The temperature of the solids is adjusted by the cooling sections of the kiln, so that coupled with the heat added via the reactants, there is supplied to the reaction Zone just sufiicient heat to efiect the desired reactions. When the reaction temperature rises to too high a level, as indicated by suitably placed conventional temperature-measuring devices well known in the art, an adjustment must be made in the cooling section of the kiln to bring the system back into heat balance. The valve 51' in the drain conduit 23 is adjusted to maintain the flow rate of solids through the regenerator at the desired flow rate and to maintain acontinuous column of solidsthrough at least the burning section of the vessel.

Although the invention has been described as an improved kiln, it is contemplated that a separate cooler may be designed according to these principles. It is less desirable to have the cooler separate from the kiln because the catalyst circulation rate must be maintained high to prevent heat damage in the kiln. This limits conditions in the reaction zone to a high catalyst to oil ratio. This invention, therefore, when applied to an improved kiln, permits greater flexibility of operation than other proposed systems of cooling the contact material, and is preferred in that form.

This invention is not intended to be limited to the specific embodiments shown above, being broad in its application and'intended to cover all changes and modifications'which do not constitute departures from the spirit and scope of the invention.

I claim:

1. The method of cooling at particle-form contact material which comprises: passing at least one stream of contact material downwardly within a cooling zone, as a laterally-confined column of contact material occupying substantially less than the total cross-sectional area of the cooling zone, discharging the contact material from the bottom of said column, to expand laterally to cover the entire cross-section of the zone, gravitating the material downwardly through upright open-ended passages distributed across the cross-section of the zone below the laterally-confined column, said passages possessing a multiplicity of cooling conduits for contacting and cooling the descending contact material, at least one of said passages being located substantially directly below said laterally-confined column and at least one of said passages being laterally displaced therefrom, lowering the level at which said column is expanded laterally in response to a need for less cooling, so that at least the major portion.

contact material into the upper portion of said cooling zone, so as to replenish the laterally-confined column and f withdrawing contact material from the cooling zone at a controlled rate, so as to maintain a substantially 0a-- tinuous column of contact material through the zone at all times.

2. The method 'for the regeneration of a spent catalyst which is withdrawn from a previous reaction with hydrocarbons and is contaminated witha coke deposit which comprises: passing the contaminated catalyst downwardly as a'substantially compact column through a confined regenerationzone, passing an oxygen-containing gas into contact with the catalyst to effect removal of coke by burning, restricting the catalyst at at least one level to a multiplicity of flow paths of cross-,secion substantially less than the cross-section of the regeneration zone, said laterally-restricted flow paths being distributed across the regeneration zone, releasing the contact material at the lower end of said flow paths to expand laterally, so as to cover the entire cross-section of the zone, gravitating the material downwardly in said zone through upright openended passages which are distributed across the entire zone, said passages possessing a multiplicity of cooling conduits distributed therethrough, so as to contact and cool the catalyst during passage through the passages, some of the passages being located below the restricted flow paths and other of the passages being located laterally displaced therefrom, lowering the level at which said catalyst is released to expand laterally from said flow paths, in response to a change in the catalyst temperature, sothat at least the major portion of the flow of contact material is restricted to those passages below the restricted flow paths and no more than a minor portion of the, flow of catalyst is through those passages laterally displaced from said restricted flow paths, whereby less heat is extracted from the catalyst, passing a cooling medium through all the cooling conduits, so as to maintainall the cooling conduits at all times a substantially diflerent tem perature than said catalyst, introducing catalyst into the upper portion of said regenerating zone, so as to replenish the column of catalyst, and withdrawing catalyst from the regeneration zone at a controlled rate, so as to maintain a substantially continuous column of catalyst through the zone at all times. 1 v

3. The method for the regeneration of a spent catalyst which is withdrawn from a previous reaction with hydrocarbons and is contaminated with a coke deposit which comprises: passing the contaminated catalyst downwardly as a substantially compact column through a confined regeneration zone, passing an oxygen-containing .gas into contact with the catalyst to eflect removal of coke by burning, restricting the catalyst column at at least two levels to a multiplicity of flow paths of cross-sectionsubstantially less than the cross-section of the regeneration zone, the flow paths being distributed across the zone with the flow paths at one level being staggered horizontally with respect to the flow paths at the next lower level, releasing the contact material cat the lower end of said flow paths to expand laterally, so as to cover the entire crosssection of the zone, gravitating the materialdownwar-dly below the flow paths through laterally-separated, openended passages distributed uniformly across the regeneration zone, said passages possessing a multiplicityof cooling conduits distributed therethrough, so as to contact and cool the catalyst during transfer through the passage,-

some of the passages being located directly beneath the restricted flow paths and the remainder of the passage being located laterally displaced therefrom, lowering the lower end of said restricted flow paths, where the catalyst is released to expand laterally, in response to a change in catalysttemperature, so that substantially the entire catalyst flow is through thosepassages directly beneath the restricted flow paths, whereby less heat is extracted from the catalyst, passing a cooling medium through all the cooling conduits at all times at a substantially different temperature than said catalyst, introducing catalyst into theupper portion of said regeneration zone and withdrawing catalyst'fromsaidzone at a controlled rate, so as to maintain a substantially continuous column of contact material through the zone at all times.

4. The method for the regeneration of a spent catalyst which is withdrawn from a previous reaction with hydrocarbons and is contaminated with ,a coke deposit which comprises: passing the contaminated catalyst downwardly as a substantially compact column through a confined regeneration zone, passing an oxygen-containing gas into contact with the catalyst to effect removal of coke by burning, restricting the catalyst at at least one levelto a multiplicity of ,flow paths of cross-section substantially less than the cross-section of the regeneration zone, said laterally-restricted flow paths being distributed across the regeneration zone, introducing at least a portion of the oxygen-containing gas into the zone at the level of the restricted flow paths, in the space between the flow paths, releasing the catalyst at the lower end of said flow paths to expand laterally, so as to cover the entire cross-section of the zone, gravitating the material downwardly through upright, open-ended passages which are distributed across the entire zone, said passages being traversed by a multiplicity of cooling conduits distributed therethrough, so as to contact and cool the catalyst during transfer through the passages, some of the passages being located below the restricted flow paths and other of the passages being located laterally displaced therefrom, lowering the level at which catalyst is released from said flow paths to expand laterally, in response to a change in the catalyst temperature, to limit the flow of catalyst to those passages below the restricted flow paths, whereby less heat is extracted from the catalyst, passing a cooling medium through all the cooling conduits, so as to maintain all the cooling conduits at all times at a substantially different temperature than said catalyst, introducing catalyst into the upper portion of said regeneration zone, and withdrawing catalyst from the bottom of the zone at a controlled rate, so as to maintain a substantially con-,

tinuous column of catalyst through the zone at all times.

5. Apparatus for cooling a particle-form contact material which comprises in combination: an upright housing, at least one substantially vertical passageway within said housing, said passageway having a crosssection substantially smaller than that of said housing, a plurality of substantially vertical partitions located across the housing beneath the passageway, for dividing the housing into several substantially vertical flow paths, at least one of which is located beneath a passageway and at least one of which is located laterally displaced from said passageway, means for raising and lowering the lower end of, said passageway, for controlling the number of flow paths filled with contact material, heat exchanging tubes distributed across said housing at the level of said, vertical partitions, means for supplying heat-exchanging fluid to said tubes and means for Withdrawing heat exchanging fluid from said tubes, means for supplying contact material continuously to the top of said passageway in said housing ,andmeans for withdrawing contact material continuously from the lower portion of said housing.

6. A kiln for regenerating a spent catalyst which comprises in combination: an upright housing, at least one substantially vertical passageway within said housing, said passageway having a cross-section at its lower end substantially smaller than that of the housing, a plurality of substantially vertical partitions located across the housing-beneath the passageway, for dividing the housing into several substantially vertical flow paths, at least one of which is located in vertical alignment with the passageway and at least one of which is located laterally displaced from said passageway, means for adjusting the level of the lower end of said passageway, so as to provide control over the number of the flow paths vfilled with catalyst, cooling tubes distributed across said housing at the level of said vertical partitions, means for supplying cooling fluid to said tubes and means for withdrawing cooling fluid from said tubes, a. catalyst inlet in the top of said housing, a catalyst outlet in the bottom of said housing, means for introducing a combustion-supporting gas into said housing at at least one level and means for withdrawing flue gas from said housing at at least one level, vertically displaced from said gas inlet means.

7. A kiln for regenerating a spent catalyst which comprises in combination: an upright housing, at least two partitions horizontally disposed across the housing, a plurality of depending conduits attached to said partitions, distributed across the partitions, with axes of the conduits in one partition being displaced in a horizontal plane intermediate the axes of adjacent conduits in the next lower partition, substantially vertical partitions located across the housing below the conduits, so as to divide the housing into several substantially equal flow paths, the tops of the partitions being located a spaced distance below the lower ends of the conduits, so that imaginary frusto-conical surfaces, formed by revolving a line, drawn downwardly and outwardly from the lower edge of the conduits at about 30 degrees with the horizontal, about the axis of each conduit, intersect in a horizontal plane above the upper edge of said vertical partitions, sub

stantially vertical extension members located about said conduits, means for raising and lowering said extension members about said conduits, cooling conduits uniformly distributed across the housing at the level of the vertical partitions, means for supplying cooling fluid to said cooling conduits and means for withdrawing cooling fluid from said conduits, a catalyst inlet in the top of said housing and a catalyst outlet at the bottom of said housing, gas inlet manifolds located across said housing at staged levels along the length thereof and gas outlet manifolds at similarly staged levels along the length of the housing, at levels intermediate the levelsof the gas inlet manifolds.

8. A kiln for regenerating a spent catalyst which comprises in combination: an upright housing, at least two partitions horizontally disposed across the housing, a plurality of depending conduits attached to said partitions, distributed across the partitions, with axes of the conduits in one partition being displaced in a horizontal plane intermediate the axes of adjacent conduits in the next lower partition, substantially vertical partitions located across the housing below the conduits, so as to divide the housing into several substantially equal flow paths, the tops the lower ends of the conduits, so that imaginary frustoconical surfaces, formed by revolving a line, drawn downwardly and outwardly from the lower edge of the conduits at about 30 degrees with the horizontal, about the axis of each conduit, intersect in a horizontal plane above the upper edge of said vertical partitions, substantially vertical extension members located about said conduits, means for raising and lowering said extension members about said conduits, cooling conduits uniformly distributed across the housing at the level of the vertical partitions, means for supplying cooling fluid to said cooling conduits and means for Withdrawing cooling fluid from said conduits, a catalyst inlet in the top of said housing and a catalyst outlet at the bottom of said housing, a plurality of gas inlet means, located at staged levels along the length of the housing, one of said means comprising the horizontal partition and depending conduits in combination, gas conduits connected to said means, means defining apertures in said partitions uniformly distributed across said partitions, bafiles located a spaced distance above said apertures, to prevent catalyst from flowing through said apertures, whereby the gas introduced below the partition flows both upwardly through the apertures and downwardly through the housing, gas withdrawal means located at staged levels along the vertical length of said housing, intermediate said inlet means, and gas conduits attached to said withdrawal means, for removal of gas from the housing.

References Cited in the file of this patent UNITED STATES PATENTS 2,417,393 Evans Mar. 11, 1947 2,561,408 Peavy July 24, 1951 2,561,409 Ardern July 24, 1951 2,621,148 Barker Dec. 9, 1952 2,741,603 Fahnestock Apr. 10, 1956 

1. THE METHOD OF COOLING A PARTICLE-FORM CONTACT MATERIAL WHICH COMPRISES: PASSING AT LEAST ONE STREAM OF CONTACT MATERIAL DOWNWARDLY WITHIN A COOLING ZONE, AS A LATERALLY-CONFINED COLUMN OF CONTACT MATERIAL OCCUPYING SUBSTANTIALLY LESS THAN THE TOTAL CROSS-SECTIONAL AREA OF THE COOLING ZONE, DISCHARGING THE CONTACT MATERIAL FROM THE BOTTOM OF SAID COLUMN, TO EXPAND LATERALLY TO COVER THE ENTIRE-CROSS-SECTION OF THE ZONE, GRAVITATING THE MATERIAL DOWNWARDLY THROUGH UPRIGHT OPEN-ENDED PASSAGES DISTRIBUTED ACROSS THE CROSS-SECTION OF THE ZONE BELOW THE LATERALLY-CONFINED COLUMN, SAID PASSAGES POSSESSING A MULTIPLICITY OF COOLING CONDUITS FOR CONTACTING AND COOLING THE DESCENDING CONTACT MATERIAL, AT LEAST ONE OF SAID PASSAGES BEING LOCATED SUBSTANTIALLY DIRECTLY BELOW SAID LATERALLY-CONFINED COLUMN AND AT LEAST ONE OF SAID PASSAGES BEING LATERALLY DISPLACED THEREFROM, LOWERING THE LEVEL AT WHICH SAID COLUMN IS EXPANDED LATERALLY IN RESPONSE TO A NEED FOR LESS COOLING, SO THAT AT LEAST THE MAJOR PORTION OF THE FLOW OF CONTACT MATERIAL IS THROUGH THOSE PASSAGES BENEATH THE COLUMN AND NO MORE THAN A MINOR PORTION OF THE FLOW OF CONTACT MATERIAL IS THROUGH THOSE PASSAGES LATERALLY DISPLACED FROM SAID COLUMN, PASSING A COOLING MEDIUM THROUGH ALL THE COOLING CONDUITS, SO AS TO MAINTAIN THE COOLING CONDUITS AT ALL TIMES AT A SUBSTANTIALLY DIFFERENT TEMPERATURE THAN SAID CONTACT MATERIAL, INTRODUCING CONTACT MATERIAL INTO THE UPPER PORTION OF SAID COOLING ZONE, SO AS TO REPLENISH THE LATERALLY-CONFINED COLUMN AND WITHDRAWING CONTACT MATERIAL FROM THE COOLING ZONE A CONTROLLED RATE, SO AS TO MAINTAIN A SUBSTANTIALLY CONTINUOUS COLUMN OF CONTACT MATERIAL THROUGH THE ZONE AT ALL TIMES.
 5. APPARATUS FOR COOLING A PARTICLE-FORM CONTACT MATERIAL WHICH COMPRISES IN COMBINATION: AN UPRIGHT HOUSING, AT LEAST ONE SUBSTANTIALLY VERTICAL PASSAGEWAY WITHIN SAID HOUSING, SAID PASSAGEWAY HAVING A CROSS-SECTION SUBSTANTIALLY SMALLER THAN THAT OF SAID HOUSING, A PLURALITY OF SUBSTANTIALLY VERTICAL PARTITIONS LOCATED ACROSS THE HOUSING BENEATH THE PASSAGEWAY, FOR DIVIDING THE HOUSING INTO SEVERAL SUBSTANTIALLY VERTICAL FLOW PATHS, AT LEAST ONE OF WHICH IS LOCATED BENEATH A PASSAGEWAY AND AT LEAST ONE OF WHICH IS LOCATED LATERALLY DISPLACED FROM SAID PASSAGEWAY, MEANS FOR RAISING AND LOWERING THE LOWER END OF SAID PASSAGEWAY, FOR CONTROLLING THE NUMBER OF FLOW PATHS FILLED WITH CONTACT MATERIAL, HEAT EXCHANGING TUBES DISTRIBUTED ACROSS SAID HOUSING AT THE LEVEL OF SAID VERTICAL PARTITIONS, MEANS FOR SUPPLYING HEAT-EXCHANGING FLUID TO SAID TUBES AND MEANS FOR WITHDRAWING HEAT EXCHANGING FLUID FROM SAID TUBES, MEANS FOR SUPPLYING CONTACT MATERIAL CONTINUOUSLY TO THE TOP OF SAID PASSAGEWAY IN SAID HOUSING AND MEANS FOR WITHDRAWING CONTACT MATERIAL CONTINUOUSLY FROM THE LOWER PORTION OF SAID HOUSING. 